Preheat oven to 350°F. In a pan mix 1 1/2 cups sugar and 1/3 cup water. Cook over low heat until sugar dissolves. Raise heat to medium-high; cook for 15 minutes, until mixture turns deep amber, swirling pan every few minutes. Divide caramel between 8 6-oz. ramekins.
Warm milk over medium heat until it simmers. Whisk 1/2 cup sugar, eggs, salt and vanilla in a bowl. Whisking constantly, slowly pour in hot milk. Strain, then pour mixture into ramekins over caramel.
Place ramekins in a large baking dish. Pour in hot water until it's halfway up sides of ramekins. Bake until set, 50 minutes. Remove ramekins to a rack to cool. Cover each with plastic; chill for 8 hours.
Melt chocolate; cool to room temperature. On a parchment-lined baking sheet, draw 8 circles as wide as ramekin bottoms. Turn parchment over. Pour chocolate into a ziplock bag; seal it and snip off a corner. In each circle pipe 5 circles and 8 spokes. Refrigerate to set.
Draw a knife around inside edge of ramekin; invert crème caramel onto a plate. Gently lift a web and place on top of custard. Repeat with remaining custards and serve.